This invention pertains to a hand tool and more particularly, to an adjustable gripping tool which, as a result of manual operation, self-energizes, automatically configures to engage differently dimensioned and shaped workpieces and de-energizes upon release of actuating force.
Various types of adjustable gripping tools are known in the art. Specifically, several known adjustable gripping tools are embodied in the form of a “crescent” wrench, an adjustable socket wrench, pipe wrench, vice grips, crimpers, bolt and nut cutters, pipe and tube cutters, and various other “plier-type” gripping tools. A crescent wrench is an adjustable open end wrench that has stationary rotatable screw which engages a toothed rack formed on a first jaw element movable with respect to the second jaw element extending from the first element. The adjustable socket wrench includes a shell housing movable elements, such that movement of the first element with respect to the shell causes the elements to move with respect to the shell in order to engage the workpiece. One cutting tool version has adjustable cutting jaws that when tightened and rotated around a tube score and cut the tube. Another version of the cutting tool uses a blade cutting mechanism. The plier-type devices include a pair of first elements connected in such a manner so as to move at least two jaws toward one another in order to engage the workpiece. The crimping tools provide various functions, such as specialty segmented dies that expand or contract via interaction of a tapered boy with a fixed diameter or  a plier-type device crimper with jaws that have been modified as a special head to crimp the workpiece.
Each of the prior art devices have disadvantages. The crescent wrench is not automatically resizable during use. The socket device is limited in its effective range of dimensional capability. In other words, a large number of sockets is needed to service a relatively standard range of workpieces, the workpieces must have a standard configuration and the workpieces must be engaged axially.
The plier-type devices fail to engage the workpiece evenly around or within the circumference with proper offsetting forces and stability which aides in operation of the tool. The plier-type devices also concentrate the applied mechanical forces in a point-loading configuration creating pressure points and stress risers on the workpiece surface.
The tube cutting devices cannot be used with one hand. Another disadvantage of tube cutting devices, in particular, knife blade cutters, is that the tubing is often distorted as a result of the asymmetrical cutting forces applied by the blade against the tube. Other tube cutting devices, such as screw-and-wheel-type tube cutters require continuous rotation of the cutting wheel around the circumference of the tube while simultaneously increasing the force applied by the cutting wheel to the tube in order to increase the cutting depth.
Prior art crimping devices cannot create symmetrically balanced crimps with a simple hand tool. For example, crimping a metal sleeve  on a hydraulic hose requires a press and a proper die for proper application. Also all of the previously available gripping tools either loosely hold the workpiece or hold the workpiece in a manner that concentrates and focuses the gripping forces in a point pressure-loading configuration. This concentration of gripping forces is on certain points concentrates the force and serves to oftentimes deform the workpiece. Also the previously available tools for wrench applications could not be easily sized to the workpiece.
Therefore, there exists a need in the prior art for an adjustable gripping tool which, as a result of manual operation, self-energizes the tool action, may be automatically sized and resized to engage a workpiece, de-energizes upon release of actuation force, that has a broad range of dimensional capability, engages workpieces axially and radially and provides offsetting forces for stability in operation. Beyond the ability to resize the gripping range, the gripping tool of the present invention symmetrically translates the force applied to the gripping tool onto the workpiece in a symmetrically balanced and mechanically advantaged and efficient way. Thus, an even distribution of gripping and rotational force about the workpiece is achieved; whereby allowing for the most efficient distribution of mechanical stress about the workpiece. For any given force required to manipulate the workpiece the present invention will accomplish the work with the minimal distortion of the workpiece by distributing the work force over the largest area of the workpiece. Other advantages of the adjustable gripping tool of the present invention include decreased costs, increased productivity and multi-access  engagement of the workpiece resulting in a mechanically advantaged, efficient, even and balanced distribution of working forces.